Compounds prepared from aluminium hydride-trialkyl amine and decaborane

ABSTRACT

1. Organo metallic compounds of the formula: (R3N.AlH2)2B10H12, wherein R is an alkyl group having from one to five carbon atoms.

United States Patent [111 3,624,117

] 72] Inventors Edward J. Bartoszek 5 R feren e Cited Norristown Pa.

, 1 TE P NTS Donald J. Mangold, New Haven, Conn. UNITED STA S ATE {21] A N 135,411 3,342,814 9/1967 Hogsett et al -60/448 R [22] Filed Aug. 30, 1961 Primary Examiner-Leland A. Sebastian Patented 197! Allorneys- Robert H. Bachman, Joseph Fleischer, Henry [73] Assignee Olin Mathieson Chemical Corporation Prusaczyk, Paul E. Rochford. Richard S. Strickler. John D.

[54] COMPOUNDS PREPARED FROM ALUMINIUM HYDRlDE-TRIALKYL AMINE AND DECABORANE [50] Field of Search 260/448,

Wilkins. Gordon D. Byrkit, Walter D. Hunter, Edward J. Mahler, Robert Alpher and George J. Koeser CLAIM: I. Organo metallic compounds of the formula:

atoms.

COMPOUNDS PREPARED FROM ALUMINIUM HYDRIDE-TRIALKYL AMINE AND DECABORANE This invention relates to organo metallic compounds and to a method for their preparation. More particularly this invention relates to organo metallic compounds of the formula:

l a 2 ]2 io 12 wherein R is an alkyl group having from 1 to carbon atoms.

The novel organo metallic compounds are prepared by reacting decaborane with an aliphatic tertiary amine adduct of aluminum hydride having the formula:

AlH -R N wherein R has the same meaning as previously described. The reaction proceeds as shown in the following equation:

B, H, +2AlH R N-*2H +[R;,N-AlH l B H wherein R is an alkyl group having from 1 to 5 carbon atoms. The reaction is conveniently carried out in the presence of an inert solvent which can be a paraffin hydrocarbon such as pentane, hexane, or heptane; or a lower dialkyl ether such as diethyl ether, di-n-propyl ether, ethyl n-propyl ether, diisopropyl ether, methyl propyl ether, methyl butyl ether, ethyl butyl ether. etc. Aromatic hydrocarbons such as benzene, toluene, or xylene may also be employed but product yields are lower.

Aliphatic tertiary amine adducts of aluminum hydride useful as starting materials include the adduct of trimethylamine, triethylamine, tri-n-propylamine, tri-isopropylamine, triisobutylamine, tri-isoamylamine, tri-amylamine, etc. Mixed aliphatic tertiary amine adducts of aluminum hydride including the adduct of methyldiethylamine, methyldiisopropylamine, n-butyldiamylamine, etc. are also suitable starting materials. The aluminum hydride adducts described can be conveniently prepared by methods well known in the art. These adducts can be prepared, for example, by reacting the corresponding aliphatic tertiary amine hydrochloride salt with lithium aluminum hydride in the presence of a lower dialkyl ether.

The reaction of this invention can be carried out at a temperature of from about 20 C. to about +80 C. with the preferred temperature being from about 0 C. to about 50 C. Depending on the temperature employed, the reaction time can be varied widely from about 0.5 to about 80 hours or more. In general the stoichiometric quantity of the aliphatic tertiary amine adduct of aluminum hydride will be reacted with decaborane although an excess of the adduct can be employed to promote completion of the reaction if desired. After the reaction has been completed, the solid organo metallic compound produced can be separated from the reaction mixture by conventional means such as by filtration or centrifugation and the solvent remaining can be removed from the product by drying under vacuum.

The organo metallic compounds produced by the process of this invention can be employed as ingredients of solid propellant compositions in accordance with general procedures which are well understood in the art, inasmuch as the solids produced by practicing the present process are readily oxidized using conventional solid oxidizers, such as ammonium perchlorate, potassium perchlorate, sodium perchlorate, ammonium nitrate and the like. In formulating a solid propellant composition employing one of the materials produced in accordance with the present invention, generally from l0 to 35 parts by weight of the organo metallic compound and from 65 to 90 parts by weight of oxidizer, such as ammonium perchlorate, are present in the final propellant composition. In the propellant, the oxidizer and the produce of the present process are formulated in intimate admixture with each other, as by finely subdividing each of the materials separately and thereafter intimately admixing them. The purpose in doing this, as the art is aware, is to provide proper burning characteristics in the final propellant. In addition to the oxidizer and the oxidizable material, the final propellant can also contain an artificial resin generally of the urea-formaldehyde or phenol-formaldehyde type, the function of the resin being to give the propellant mechanical strength and at the same time improve its burning characteristics. Thus, in manufacturing a suitable propellant, proper proportions of finely-divided oxidizer and finely-divided organo metallic compound can be admixed with a high solids content solution of a partially condensed urea-formaldehyde or phenol-formaldehyde resin, the proportions being such that the amount of the resin is from about 5 to 10 percent by weight, based upon the weight of the oxidizer and the organo metallic compound. The ingredients are thoroughly mixed with simultaneous removal of the solvent, and following this the solvent-free mixture is molded into the desired shape, as by extrusion. Thereafter, the resin can be cured by resorting to heating at moderate temperatures. For further information concerning the fonnulation of solid propellant compositions, reference is made to U.S. Pat. No. 2,622,277 to Bonnell et al. and US. Pat. No. 2,646,596 to Thomas et al.

The following examples illustrate various embodiments falling within the scope of this invention.

EXAMPLE I In a dry box with a nitrogen atmosphere a solution of 8.02 grams (0.065 mole) of decaborane in 500 ml. of n-pentane which had been previously dried over sodium was placed in a l000 ml., three-necked, round-bottom flask. A slurry of aluminum hydride-trimethylamine adduct (11.58 grams 0. I30 mole) prepared by the reaction of lithium aluminum hydride with trimethylamine hydrochloride in diethyl ether and identified by infrared analysis was placed in a 500 ml. flask in the same dry-box. The flasks were then removed from the drybox and while maintaining a nitrogen purge the 1000 ml. reaction flask was attached to the remainder of the apparatus which had been thoroughly purged with nitrogen and which consisted of a cold finger condenser cooled with a dry-ice acetone mixture to a temperature of 78 C., a'cold trap cooled with a dry-ice acetone bath to a temperature of 78 C., a mercury bubble-off and a wet test meter. The apparatus was arranged so that gases leaving the I000 ml. reactor passed first through the cold finger condenser then through the trap maintained at 78 C. and finally through the wet test meter. The flask containing the aluminum hydride-trimethylamine slurry was attached to the reactor through two right angle glass bends with standard taper joints in such a manner that it could be rotated to admit the slurry to the reaction flask. The l000 ml. reaction flask was also provided with a magnetic stirrer.

In small increments the trimethylamine aluminum hydride slurry was added to the decaborane solution over a l0 minute period. As the adduct was added hydrogen was evolved immediately and at the same time a white precipitate formed which gradually turned yellow as the reaction proceeded. During a period of about 8.5 hours a total of 2.943 liters (0.13 mole) of hydrogen was evolved and only a negligible amount of hydrogen was evolved during the following 8 hours. The slurry residue containing the solvent and yellow, finely divided, solid was filtered in a dry-box through a fritted glass filter and the precipitate was washed with three ml. portions of dry n-pentane. The solvent-wet solid was then placed in a round bottom flask and maintained under reduced pressure for about 5 hours in order to remove the residual solvent. A total of 18.86 grams (97.9 percent of the theoretical yield) of [(CH hN'All'lfl B l-l the desired product, was obtained.

The product was analyzed for aluminum, boron, nitrogen, carbon and hydrogen and the following results were obtained.

EXAMPLES ll thru V A number of additional experiments were carried out in the same manner as described in Example I and utilizing the same l7.94 grams (0.20 mole) of decaborane dissolved in 250 ml. of benzene was added slowly to l2.47 grams (0.10 mole) of aluminum hydride trimethylamine adduct dissolved in ISO ml. of benzene. After about 20 hours a yellow product containing apparatus with certain minor changes. in these examples the [(CHUSNAIHZEBIOH was obtained cold trap was maintained at a temperature of l96 C. by whatis claimedis.

means of a liquid nitrogen bath and the adducts slurried in the organo metallic compounds of the formula;

particular solvent utilized were added to the decaborane solu [R N-Aifl l zB l-l {ion from a calibrated addition funnel A gas sampling bulb wherein R is an alkyl group having from I to 5 carbon atoms.

also was placed in the system after the trap maintained at 2 CI-[ N-A1H B H 196 C. to permit the king of S mp f h -g f 3. The process of preparing organo metallic compounds of analysis. The experimental conditions and the results obtained the [R N-AlH B H in examples ll V are set forth in table l which follows. wherein R is an alkyl group having from 1 t0 5 Carbon HI TABLE I [Reaction of AlHi- N(CII with decaborane] Analysis or product Reactants (mole) Hydrogen Weight ([(CII; zNAlHzlQliiollw) (percent) evolved Time product Yield Example AlHz- N (CH3); B mliii Solvent (mole) (hours) (grams) (percent) Al if N ll 11.... 0.0649 0. 0325 n-Pentane 0.0681 76 8.8 91.5: g? i 111. 0.1452 0. 0726 110"... 0.164 67 19.5 uo.s{ H 1v. 0.114 0.057 110.... 0.134 22 16.2 95.8: 5-2 3 3 v 0. 1868 0.01134 .do..... 0. 1822 1:1 27.03 97.6: 3?

1 45 p1 ent of hydrogen evolved after 6 hours, .18 percent evolved after 3 07 percent of hydrogen evolved after 5 hours, product separated after it hours iroduet separated after 76 hoursv 22 hours.

" 98 percent of hydrogen evolved after 24 hours, product separated after 67 hours.

EXAMPLE Vl Utilizing a procedure similar to that of example l a total of l 1.90 grams (0.097 mole) of decaborane dissolved in 175 ml. diethyl ether was reacted slowly with l7.76 grams (0.195 mole) of aluminum hydride trimethylamine adduct in 400 ml. of diethyl ether. After about hours a high yield of product was obtained which by infrared analysis was shown to correspond closely to the product of example 1.

EXAMPLE Vll in this example in which benzene was employed as the solvent a procedure similar to example i was followed. A total of which comprises reacting decaborane with an adduct of the formula:

R N-AlH wherein R is an alkyl group having from i to 5 carbon atoms.

*ggggy UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,624,117 Dated November 3 97 Inventor) Edward J. Bartoszek and Donald J. Mangold It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 6, the formula [R3N-AlH H a7 B H 2 should read [E rl-111115213 11 Column 3, line 15, "table" should read --Table--. Column 3, lines 13, 35, 39 and +2 "example" should read-Example. Column 4, in claim 1, the formula ZE N- AlH 7a2B H should read AR N-AlHJ B H Column 4, in claim 2, the formula [(CH N-AlI-I B H should read [(CI-I N'AlH;7 B H Column 4, in claim 3, before the formula insert --formu1a--.

Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attes ting Officer Commissioner of Patents 

1. ORGANO METALLIC COMPOUNDS OF THE FORMULA: (R3N-A1H2)2B10H12, WHEREIN R IS AN ALKYL GROUP HAVING FROM ONE TO FIVE CARBON ATOMS.
 2. ((CH3)3N.AlH2B10H12
 3. The process of preparing organo metallic compounds of the formula: (R3N.AlH2)2B10H12, wherein R is an alkyl group having from 1 to 5 carbon atoms, which comprises reacting decaborane with an adduct of the formula: R3N.AlH3, wherein R is an alkyl group having from 1 to 5 carbon atoms, in the presence of an inert solvent.
 4. The process of claim 3 wherein the reaction is carried out at a temperature of from about -20* C. to about +80* C.
 5. The process of claim 4 wherein the adduct is (CH3)3N.AlH3.
 6. The process of claim 4 wherein the inert solvent is n-pentane.
 7. The process of claim 4 wherein the adduct is (CH3)3N.AlH3 and the inert solvent is n-pentane. 